Spectral Signature Characterization and Remote Mapping of Oman Exotic Limestones for Industrial Rock Resource Assessment

Abstract

This study demonstrates the capability of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor data to remotely map industrial carbonate rocks known as the 'Oman exotics' of the Sultanate of Oman. We measured reflectance spectra of marble using a PIMA™ spectrometer and studied their spectral absorptions distinguishing calcite from spectral absorptions of dolomite of the same region. The spectral band 8 of ASTER is processed by simple decorrelation stretch image processing method to map the exotic limestone rock of the Nakhl region, Oman. Results showed that carbonate rocks displayed distinctive tonal variation on the image. A comparative study with the spectral band 7 of Landsat 7 (ETM+) does not discriminate the calcite-bearing marbles and associated carbonate formations in the studied area. ASTER data were also processed by the application of the Maximum Likelihood Classification (MLC), Spectral Angle Mapper (SAM) and Spectral Information Divergence (SID) image classification algorithms. The results were assessed by the production of a confusion matrix. The study shows the capability of visible near infrared (VNIR) and shortwave infrared (SWIR) spectral bands of the ASTER sensor and potential of the image processing methods to remotely identify industrial carbonate rocks and we recommend this technique to similar regions of the world.

Detection of Wakashio oil spill off Mauritius using Sentinel-1 and 2 data: Capability of sensors, image transformation methods and mapping

“…In this study, the visual interpretation of images has been considered as one of the most effective methods to study the spread of oil spills and associated features (Bradford and Sanchez-Reyes, 2011;Vergara et al, 2016). The accuracy of the mapping of Wakashio oil spill was assessed by classifying the SAR-C data and the decorrelated images of MSI data using Parallelepiped supervised algorithm and confusion matrix (Congalton, 1991;Richards and Jia, 1999;Ganasria and Dwarakisha, 2015;Rajendran et al, 2016Rajendran et al, , 2018Lee et al, 2018). The Parallelepiped algorithm is one of the most simple and accurate classification techniques works on the division of every axis of a multidimensional feature vector (Castillejo-Gonzalez et al, 2009;Ganasria and Dwarakisha, 2015;Lee et al, 2018).…”

ASTER mapping of gypsum deposits of Thumrait region of southern Oman

“…However, the absorptions around 1,500 nm and 1,900 nm are water vapor atmospheric absorption bands and cannot be well utilized, but the other absorption features at 1,750, 2,200, and 2,400 nm are well defined. Figure 5 presents a spectral plot of the industrial gypsum and the gypsum of sedimentary formations of the study area resampled to SWIR spectral bands (4 to 9) of ASTER in 1.3 to 2.5 μm (Rajendran et al ., 2018; Rajendran et al ., 2020). It shows clearly that the gypsums of study region have absorptions in the 2.2 and 2.4 μm (green and red elliptical) and the ASTER bands closer to the wavelengths can be used to discriminate gypsum occurrences.…”

Twenty Years of ASTER Contributions to Lithologic Mapping and Mineral Exploration

“…less dense minerals typically have higher abundances near the center of the active and most evolved dunes in the field, while more dense minerals and glasses appear to be more abundant along the margins of the active dune fields." ASTER data were applied to characterize limestones for industrial rock resource assessment in Oman by Rajendran et al [47]. They were able to separate dolomite from calcite-bearing marble; this has a direct application in the industrial rock business.…”